In conducting face authentication by using the face recognition device, a face image of a person to be authenticated is first registered in a face authentication device as a face of a subject person. Then, it is checked whose face a face image newly acquired matches in registration face images to identify the subject person.
In this situation, when a new person is tried to be recognized, the new person is registered as a registration image. FIG. 27 is a block diagram of a conventional face authentication device disclosed in Patent Document 1. Referring to FIG. 27, images taken by an imaging device 9 are displayed on a display device 11, and the images to be registered are selected and registered by an input device 12.